Synthesis, characterization, and reaction of aluminum halide amides supported by a bulky beta-diketiminato ligand

Monomeric aluminum chloride amides with the general formula LAl(Cl)NR2 (1, R = Me; 2, R = iPr; 3, R = SiMe 3; L = HCC(Me)N(Ar)]2; Ar = 2,6- iPr2C6H3) were prepared by selected routes. Treatment of LAlBr 2 (4) and LAlI2 with LiNMe2 yielded LAl(Br)NMe2 (5) and LAl(I)NMe2 (6), respectively. The alkylation of 1 and 2 with MeLi gave the corresponding methylated compounds LAl(Me)NR2 (7, R = Me; 8, R = iPr); however, no reaction of 3 with MeLi was observed because of steric hindrance. Subsequent fluorination of 1- 3 afforded LAl(F)NR2 (9, R = Me; 10, R = iPr; 11, R = SiMe3). Compounds 1-11 were characterized by multinuclear NMR, electron impact mass spectrometry, and IR. The constitution of compounds 1-3 was confirmed by single-crystal X-ray diffraction studies.